Providing immediate feedback improves recycling and composting accuracy.

The volume of solid waste has increased significantly in the past century, directly contributing to global environmental problems. Public engagement with waste sorting is crucial to the diversion of solid waste from landfill and the reduction of contamination in waste streams. The current study aims to promote recycling and composting accuracy via a digital sorting game that provides immediate feedback. In this game, participants manually sorted items into four bins (food scraps, recyclable container, paper, and garbage) via a computer interface, and received immediate feedback on their performance after each trial. We found that immediate feedback improved sorting accuracy as measured by correct key presses (Experiment 1) or motion trajectory (Replication 1), even when feedback was no longer provided. This improvement in sorting accuracy remained a week after playing the game (Replication 2). We then implemented this game in residences, and found that after residents played this game, the weight of compost materials increased while the contamination rate decreased (Experiment 2). These findings suggest that providing immediate feedback in a digital sorting game can be an effective tool to engage and educate the public to increase recycling and composting rates.